Secondary Navigation

Main Navigation

Q&A /

Black Mold

DEAR TIM: We accepted a contract to sell our home. After the home inspector discovered some mold, a mold expert was brought in. The two areas of mold, each one measuring about 3 foot by 3 foot, were caused by a burst water pipe that was immediately fixed and the water dried up within 48 hours. Do I have to have the mold professionally cleaned? What about the chronic mold in my bathroom? Barbara S., Lancaster, PA

DEAR BARBARA: To a large degree, I think this mold hysteria has gotten a little bit out of hand. Don't get me wrong, there are molds that are highly toxic and other common molds that can produce life-threatening allergic reactions in highly sensitive people. But everyone needs to understand that mold is a part of the food chain and we actually need it. Mold is just about everywhere outside your home and in many foods we eat. It is just not a good idea to have mold growing on things inside your home.

Black mold such as this can blossom in days under the right conditions. PHOTO BY: Tim Carter

There are over 30,000 known types of molds so you can see that even professional micro-biologists could spend a lifetime and not be an expert about each one. But the rest of us who do not actively study mold on a professional level need to know that mold growth, for the most part, can be easily stopped in a home. The secret is to simply keep surfaces inside your home dry.

Mold spores are already in everyone's home unless you happen to live in a house built like the sterile rooms at the Centers for Disease Control and Prevention where scientists wear special moonsuits. Mold spores are invisible to our eyes as they often are only 3 microns across. The smallest object the average person can see with the naked eye is often 50 microns or larger in size. The spores are actual seeds that sprout and grow into microscopic plants when they come into contact with water. They are everywhere in the average home just waiting for water.

The mold spores in your home must be in contact with an organic substance like food, dust, paper, cardboard, dirt, leather, etc. in order to grow. Surfaces such as ceramic tile and even stainless steel can have mold on them, but the mold is growing in and on a thin invisible layer of dirt, grease, oils, body skin cells, etc. As soon as the spores come into contact with water, the outer surface of the spore dissolves and starts to soften the organic material. Small roots grow out of the spore much like a regular plant into the softened organic food source.

Some molds need very little moisture to flourish while other molds need lots of water to quench their thirst. But when you consider how small the mold spores are, you can see it doesn't take much water to get them to grow. In fact, the water needed to start and support the mold's life cycle can be an invisible fog of tiny water droplets that are also invisible to your eyes.

This is one reason people have so much trouble controlling mold growth in bathrooms such as yours. When you take a steamy shower you see the mirror fog up. This same fog covers the ceiling and walls as well and is the water needed to fuel the growth of the pesky mold. This is why bathrooms must have powerful fans that duct the humid air to the exterior of your home, not up into your attic.

After you have bathed, tub and shower walls and shower doors should be squeegeed down to direct as much liquid water as possible to the drain. Bathroom shower curtains need to be shaken to remove as much water as possible. Leave your shower door, shower curtain and bathroom door open when you leave the room. You want all surfaces to dry out as rapidly as possible.

The mold the inspector found does not have to be professionally cleaned. Since each area is less than 10 square feet, it falls within the guidelines of do-it-yourself cleanup as stated by the Environmental Protection Agency. When surface areas get larger than 10 square feet, it might be necessary to call in a professional that works with special protective clothing and breathing apparatus and is able to minimize or eliminate the spread of mold spores throughout the rest of the house.

It is very wise to wear an N-95 respirator when cleaning mold. The cleaning process can liberate additional mold spores into the air that can cause mold to spread and more importantly, create health risks to those people who are allergic to that particular mold.

It is a good idea to lightly mist the area to be cleaned with a biocide solution such as regular chlorine bleach and water before you start to clean it. Wear rubber gloves and goggles that do not have ventilation holes. You want to avoid getting mold on your skin and in your eyes.

If possible, try to place a large fan in a window in the room you are cleaning to exhaust mold spores outdoors. Imagine the air being filled with smoke. The air will be filled with mold spores as you disturb the surface you are cleaning, so try to exhaust as many spores as possible outdoors.

Be sure to rinse well all cleaning tools, rags, etc. immediately after cleaning. Wash all clothes immediately so they do not grow mold in the clothes basket or hamper. Dry all cleaned surfaces with rags, paper towels or a fan. Remember, the key to stopping mold growth in its tracks is to prevent water from getting on any interior surfaces of your home.